Hitching and unhitching a gooseneck trailer to a truck requires considerable stretching and climbing on the part of the user. Once the trailer is lined up with the ball of the hitch, the user must generally climb into the bed of the truck to attach the socket end of the gooseneck to the ball, and then attach the safety chains to the hitch plate. The climbing, leaning, and kneeling required to hitch and unhitch a gooseneck trailer may be difficult for people with back or knee injuries, or for those who are advanced in age. Accordingly, there is a need for a trailer hitch adaptor assembly that allows the user to quickly hitch and unhitch a gooseneck trailer without climbing into the bed of a truck.